(1) Technical Field
This invention relates to heat exchangers having multiple fluid vaporizing structures such as may be employed to vaporize water and a hydrocarbon separately and simultaneously.
(2) Description of the Prior Art
Prior heat exchangers of a similar type may be seen in U.S. Pat. Nos. 806,139, 1,815,938 and 3,468,371. The device of the U.S. Pat. No. 806,139 forms relatively short passageways arranged in a spiral pattern in a common hollow body which is itself cylindrical.
In U.S. Pat. No. 1,815,938, a pair of fluid flow conduits are formed between outer and inner cylindrical members by spiral configurations in the outer surface of the inner cylindrical member and the addition of spiral gaskets.
U.S. Pat. No. 3,468,371 arranges three concentric tubular members, one of which has a spiral corrugation therein to provide separate spiral passageways.
The present invention discloses a simplified more efficient heat exchanger particularly adapted for vaporizing a hydrocarbon such as gasoline or fuel oil and water separately and simultaneously and is formed primarily of a cylindrical body defining a cylindrical bore and a sleeve having separate spiral thread-like configurations in its exterior press fit in said bore. Simple closures for the bore and ports in the cylindrical body produce a simple, inexpensive and efficient heat exchanger when a source of heat such as an electrical resistance heating element is positioned in the sleeve.